We could add the compaction of history steps as a maintenance task.
Several ways to do it with steps with end date older than a given date or interval (like more than 6 months):

1. Compact all steps as a unique step with a specific action id for "archived" steps
2. Compact all following steps of same action id with their original action id

Note:

• Start date is the start date of the first step.
• End date is the end date of the last step.
• Comments have to be concatenated, and a specific comment should be added to indicate the compaction and the date of the compaction.